FIG. 1 illustrates a conventional resource allocation procedure in a wireless communication system.
Referring to FIG. 1, a Mobile Station (MS) requests an uplink bandwidth by random access in the conventional wireless communication system. The MS transmits a Bandwidth Request (BR) code to a Base Station (BS) in step S110.
Upon receipt of the BR code, the BS allocates uplink resources to the MS so that the MS may transmit a BandWidth Request (BW-REQ) message in the uplink resources in step S120.
After transmitting the BR code, the MS activates a timer. If uplink resources for transmission of a BW-REQ message are not allocated to the MS until expiration of the timer, the MS retransmits the BR code to the BS. The timer may be set to a contention-based reservation timeout value.
In step S130, the MS transmits the BW-REQ message to the BS in the allocated uplink resources. Upon receipt of the BW-REQ message from the MS, the BS allocates uplink resources to the MS, for uplink data transmission in step S140. The MS transmits data in the allocated uplink resources in step S150. In this manner, the resource allocation is a five-step procedure in the conventional communication system.
FIG. 2 is a diagram illustrating transmission timings of signaling and messages during the conventional resource allocation procedure in the wireless communication system.
Referring to FIG. 2, one frame includes five downlink subframes and three uplink subframes. Reference numeral 1 denotes transmission time points of signaling and messages, when a BR code is transmitted in a first uplink subframe, and reference numeral 3 denotes transmission time points of signaling and messages, when a BR code is transmitted in a third uplink subframe.
Uplink data is transmitted in the third frame after transmission of a BR code. Given a 5-ms frame, 15 ms is taken to transmit uplink data after a BR code is transmitted. A possible failure in contention resolution and transmission adds to the time delay.